Oral Cavities

Question 1

Describe the structure of the oral cavity:

Answer 1

Vestibule - space between cheek and teeth

Palate - closes off nasopharynx, important for eating, hard and soft palate

Fauces - opening at back to pharynx, posterior wall of pharynx

Faucial arches;
- Palatoglossal arch
- Palatopharyngeal arch
pharyngeal behind glossal

Palatine tonsil - found between arches

Uvula - projection hanging from the soft palate, aiding in speech and preventing food from entering the nasal cavity during swallowing

Question 2

Describe the oropharynx:

Answer 2

Extends from the soft palate superiorly to the epiglottis inferiorly
Lies posterior to the oral cavity communicating with it via the oropharyngeal isthmus
Involved in swallowing
Contains - palatine tonsils, Lingual tonsils and Pharyngeal constrictor muscles

Question 3

Describe the tensor veli palatini and levitator veli palatini muscles:

Answer 3

TVL;
- originates at medial pterygoid plate of the sphenoid bone + auditory tube
- inserts at palatine aponeurosis
- function =. tenses soft palate

LVP;
- origin = petrous part of temporal bone + auditory tube
- insertion = palatine aponeurosis
- function = Elevates the soft palate

Question 4

Describe the Palatoglossus and Palatopharyngeus muscles:

Answer 4

Palataglossus;
- attaches palate to tongue
- brings tongue and soft palate together

Palataphrayngeus;
- attaches palate to lateral wall of pharynx
- raises pharynx during swallowing

Question 5

What are the Suprahyoid muscles ?

Answer 5

Digastric
Stylohyoid
Mylohyoid
Geniohyoid

Function;
- raise hyoid
- depress mandible

Question 6

Describe the paired salivary glands :

Answer 6

Parotid;
- empty saliva into raw cavity via parotid duct
- pierces buccinator
- facial nerve branches with gland
- largest gland, anterior to ear

Submandibular;
- Wraps around posterior edge of mylohyoid
- duct runs anteromedially to open either side of lingual frenulum

Sublingual;
- U-shaped ridge in floor of mouth
- opens up either side under tongue
- drains into submandibular

Question 7

What are the muscles of the tongue ?

Answer 7

Styloglossus;
- styloid process to the tongue
- function is retraction and and elevate sides of tongue

Hyloglossus;
- hyoid to tongue
- depression and retraction of tongue

Genioglossus;
- internal chin to tongue and hyoid
- depression , protrusion, deviation to one side

Intrinsic muscles;
- all within the tongue
- alter tongue shape

Question 8

What innervates muscles of the tongue ?

Answer 8

Cranial nerve XII - hypoglossal nerve

Question 9

What nerves innervates the actual tongue ?

Answer 9

Sulcus terminalis divides tongue into posterior and anterior

Posterior;
- 1/3
- glossopharyngeal IX, for taste and sensation
- hypoglossal nerve for motor innervation

Anterior;
- 2/3
- taste by VII
- sensation by V3 division of trigeminal nerve
- motor innervation by hypoglossal nerve